Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Statistical Distribution of Fatigue Life of Composite Materials for Small Wind-Turbine Blades

소형풍력발전 블레이드용 복합재료의 피로수명 분포에 대한 확률론적 평가

  • Kang, Ki-Weon (Break-through Technology Center for Urban Wind Energy System, Kunsan Nat'l Univ.)
  • 강기원 (군산대학교 도시형풍력발전원천기술연구센터)
  • Received : 2011.05.16
  • Accepted : 2011.06.05
  • Published : 2011.10.01
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Abstract

This paper deals with several statistical distribution functions for the analysis of fatigue life data of composite laminates for small wind-turbine blades. A series of tensile tests was performed on triaxial glass/epoxy laminates for loading directions of $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$. Then, fatigue tests were carried out to determine the fatigue life at the aforementioned loading directions and the fatigue stresses at four levels. Two-parameter Weibull, three-parameter Weibull, normal, and log-normal distributions were used to fit the fatigue life data of the triaxial composite laminates. The three-parameter Weibull distribution most accurately described the fatigue life data measured experimentally for all the cases considered. Furthermore, the variation of fatigue life was simultaneously affected by the loading direction and fatigue stress level.

본 논문에서는 소형풍력발전시스템 블레이드 제작에 사용되는 복합재료의 피로수명 데이터에 대한 통계적 해석을 위하여 다양한 확률분포 모델의 적합성에 대한 연구를 수행하였다. 이를 위하여 삼축 유리섬유강화 복합재료를 대상으로 0$^{\circ}C$, 45$^{\circ}C$ 및 90$^{\circ}C$ 의 하중방향에 대한 인장시험을 실시하였다. 또한 상기의 하중방향에 대하여 4 수준의 피로응력준에서의 피로시험을 수행하였다. 이를 통하여 획득한 피로수명 데이터를 대상으로 1) 전체 적합성, 2) 끝단 적합성 및 3) 피로물리 일치성의 기준을 이용하여 2 모수 Weibull, 3 모수 Weibull, 정규 및 대수정규분포의 적합성을 평가하였다. 또한 피로수명의 분산에 대한 하중방향 및 피로응력의 영향 역시 검토하였다.

Keywords

References

  1. Dong, K.M., Jung, S.N. and Shin, C., 2001 "Perfomance Prediction and Structural Analysis of Counter-Rotating Wind Turbine Blade," Proceeding of The Korean Society for Aeronautical & Space Sciences, 2001, Autumn, pp.708-711
  2. Kim, J.K., Lim. D.M., Yoon, I.S. and Kang, K.W., 2006, "Fatigue Analysis of Fiber-Reinforced Composites Using Damage Mechanics," Transaction of KSME (A), Vol. 30, No. 2, pp.112-119 https://doi.org/10.3795/KSME-A.2006.30.2.112
  3. Kam, T.Y., Tsai, S.Y. and Chu, K.H., 1997, "Fatigue Reliability Analysis of Composite Laminates Under Spectrum Stress," International Journal of Solids Structures, Vol. 34, pp. 1441-1461 https://doi.org/10.1016/S0020-7683(96)00093-5
  4. Yang, J.N. and Jones, D.L., 1980, "Effect of Load Sequence on the Statistical Fatigue of Composites," AIAA Journal, Vol.18, pp.1525-1531 https://doi.org/10.2514/3.50912
  5. Tanaka, S., Ichikawa, M. and Akita, S., 1984, "A Probabilistic Investigation of Fatigue Life and Cumulative Cycle Ratio," Engineering Fracture and Mechanics, Vol. 20, pp. 501-513 https://doi.org/10.1016/0013-7944(84)90055-9
  6. Liu., Y. and Mahadevan. S, 2005, "Probabilistic Fatigue Life Prediction of Multidirectional Composite Laminates," Composite Structures, Vol. 69, pp.11-19 https://doi.org/10.1016/j.compstruct.2004.04.012
  7. Kang, K.W., Lim, D.M. and Kim, J.K., 2008, "Probabilistic Analysis for the Fatigue Life of Carbon/epoxy Laminates," Composite Structures, Vol. 85, pp.258-264 https://doi.org/10.1016/j.compstruct.2008.01.003
  8. ASTM D 3039-00, 2000, "Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials."
  9. Zhao Y.-X., Gao Q., Sun X.-F., 1998, "A Statistical Investigation of The Fatigue Lives of Q235 Steel-Welded Joints," Fatigue & Fracture of Engineering Materials & Structures, Vol. 27, pp. 781-790.
  10. Freudenthal, A. M., 1947,"The Safety of Structures," Transactions of ASCE, Vol. 112, pp. 125-180
  11. Weibull++7, 2008, Users Manual, Reliasoft Inc.
  12. Kang, K. W., Koh, S.K., Kim, D.K. and Kim, K.J., 2009, "Assessment of the Statistical Distribution of Flexural Strength of Woven-fabric Laminates with Impact-Induced Damage," Composite Structures, Vol. 90, pp.60-66 https://doi.org/10.1016/j.compstruct.2009.02.001
  13. Abernethy, R. B., 1996, "The New Weibull Handbook," 2nd Edition, SAE Professional Development, pp. 2-7.
  14. Sakin, R. and Ay, I., 2008, "Statistical Analysis of Bending Fatigue Life Data Using Weibull Distribution in Glass-Fiber Reinforced Polyester Composites," Materials and Design, Vol. 29, pp. 1170-1181. https://doi.org/10.1016/j.matdes.2007.05.005

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